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Findings by Dr. Amy Byrd and Colleagues Find the Interaction between Monoamine Oxidase A and Early Maltreatment Puts Women at Risk for Personality Pathology via Emotional Reactivity

Research consistently demonstrates that common polymorphic variation in monoamine oxidase A (MAOA) moderates the influence of childhood maltreatment on later antisocial behavior in males, with growing evidence that the “risk” allele (high vs. low activity) differs in females. These findings underscore the need for continued research regarding this gene by environment interaction (GxE) in female samples. Moreover, very little is known about how this GxE interaction functions to increase risk, or if this risk pathway is specific to antisocial behavior.

In this study, Drs. Amy Byrd, Stephen B. Manuck, Vishwajit Nimgaonkar, Kodavali Chowdari, Alison Hipwell, and Stephanie D. Stepp, along with other colleagues, expand the current literature by examining whether changes in emotional reactivity during adolescence may mediate interaction of MAOA variation and childhood maltreatment on antisocial personality disorder (ASPD) in early adulthood. In addition, the current study examined whether this hypothesized risk pathway is specific to ASPD or whether it also confers risk for other personality pathology characterized by high levels of emotional reactivity, such as borderline personality disorder (BPD). Moreover, this study broadens the largely exclusive focus on males by addressing these questions in a large, urban female sample that had been comprehensively assessed from childhood into early adulthood (Pittsburgh Girls Study). They assessed childhood maltreatment, emotional reactivity, and personality pathology via annual in-home interviews.

While direct associations between early maltreatment and later personality pathology did not vary by MAOA genotype, there was a significant difference in the indirect path via emotional reactivity during adolescence. Consistent with hypotheses, females with high-activity MAOA genotype who experienced early maltreatment had greater increases in emotional reactivity during adolescence, and higher levels of emotional reactivity predicted both ASPD and BPD symptom severity in early adulthood. Taken together, findings suggest that the interaction between MAOA and early maltreatment places women at risk for a broader range of personality pathology via effects on emotional reactivity.

Importantly, these findings have potential implications for prevention and intervention programs designed to target maltreated youth at risk for the development of ASPD and/or BPD. Prevention efforts could focus on ways to reduce emotional reactivity and/or promote adaptive strategies for managing high levels of emotional reactivity among youth exposed to childhood maltreatment. Dr. Byrd states, “Helping parents to respond to high levels of emotional reactivity in a way that validates the emotional experience, models effective coping strategies, and prevents potential escalation, as well as inadvertent reinforcement, could help to divert at-risk youth away from enduring trajectories of personality pathology.”